10:13am:Ken Rosenthal of FOX Sports tweets that the Padres will also receive a player to be named, so it's a 4-for-1 swap. The 40-man roster freeze is in effect until next week's Rule 5 Draft, so it's possible the player is a minor leaguer not on the 40-man that's eligible for the Rule 5.

10:04am:Heyman tweets that there is still work to be done as far as a contract extension for Gonzalez, and that it could take a day or two. Jon Paul Morosi of FOX Sports confirms with a source that the trade is "not completely done." (Twitter link)

9:14am:Hayes tweets that the package includes Kelly, Rizzo, and Reymond Fuentes. ESPN Boston's Gordon Edes says (via Twitter) that Theo Epstein flew from San Diego to Boston with Gonzalez, and MLB.com's Corey Brock says that Jed Hoyer implored his scouts to scour the lower level of the minors in 2010 (Twitter link). The second and third player in the deal are key.

9:01am:SI.com'sJon Heyman tweets that negotiations about a contract extension will begin shortly, and that Kelly is in fact in the deal. WEEI.com's Alex Speier adds that multiple Red Sox prospects rumored to be in the deal have yet to hear anything from the team about a trade (Twitter link).

7:39am:Olney tweets that the Red Sox flew Gonzalez into Boston to help move the process along, and he is there now.

FRIDAY, 4:46pm: The Red Sox and Padres are discussing a potential trade that would send Adrian Gonzalez to Boston, according to Gordon Edes of ESPNBoston.com. Red Sox GM Theo Epstein appears to be making "some headway" in tempting Padres GM Jed Hoyer with a package of top prospects, Edes reports.

The proposed deal would include minor league players only. Hoyer, new assistant Josh Byrnes and Padres exec Jason McLeod are all former Red Sox executives, so they know the team's system well. Other clubs also have strong interest in the first baseman.

The Padres must address multiple needs on a limited budget this offseason and trading Gonzalez and his $6.2MM salary would give the team some flexibility. However, few hitters have Gonzalez's power and they would create a hole by dealing their first baseman.

The Red Sox, who have long had interest in Gonzalez, could move Kevin Youkilis to third base to make room. A trade for Gonzalez would effectively end Adrian Beltre's tenure in Boston.